@keyframes insert-course {
    from {
        border-left: 1px solid black;
    }

    50% {
        border-left: 1px solid transparent;
    }

    to {
        border-left: 1px solid black;
    }
}

@keyframes overwrite-course {
    from {
        border-bottom: 1px solid black;
    }

    50% {
        border-bottom: 1px solid transparent;
    }

    to {
        border-bottom: 1px solid black;
    }
}
